1. Field of the Invention
This invention relates to small, self-propelled vehicles that may be used by the infirm, disabled or aged, and particularly to a personal, all-terrain vehicle for transporting a paraplegic.
2. Background Art
Self-propelled wheelchairs have been used by aged and infirm persons for personal transportation, commonly powered by an electric battery and motor, but an internal combustion engine powered version was also disclosed by Walker, U.S. Pat. No. 4,475,613. Wheelchairs are generally suitable, however, only for locomotion over smooth or paved surfaces. For self-propelled transportation over rough and uneven terrain such as stairs, mountain and forest trails, and gravel roads, vehicles mounted on a pair of tracks or endless belts, and a passenger seat mounted on the vehicle between the tracks, have been developed. See, for example, the tracked stair climbing wheelchair described by Littlejohn, et al., U.S. Pat. No. 5,123,495, and that described by Watkins, U.S. Pat. No. 4,674,584. Such tracked vehicles can be ideal for outdoor use in rugged, hilly terrain because their dual track mechanisms can provide a stable, wide stance, and excellent ability to grip loose and muddy surfaces, and uneven surfaces. Heretofore, however, the task of boarding and unboarding the tracked vehicle has been difficult for wheelchair-bound persons, especially during self-assisted transfers executed by paraplegics. When the wheelchair would be drawn up alongside and parallel to one of the track mechanisms and adjacent the passenger seat of the tracked vehicle, it would be necessary to lift and swing the entire lower body of the paraplegic up and out of the wheelchair, all the way across one track mechanism, and into the passenger seat. Self-assisted transfer from the tracked vehicle back to the wheelchair was equally difficult due to the width of the track mechanisms. Thus, there remains a need for a tracked, stable, self-propelled all-terrain vehicle designed for self-assisted transfers from and to a wheelchair.